The Meraki documentation describes this in their “Granting Microsoft Admin Consent to Cisco application” section.
If you don’t see the app in Enterprise Applications (or in App registrations), it typically means you have not yet granted consent, so from Azure’s perspective, this app hasn’t been “installed” or allowed into your tenant.
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
Please, if this post was useful, leave your kudos and mark it as solved.